1. Field of the Invention
This invention relates to a solid state color television camera, and particularly to a color camera in which an interlacing pickup system is employed.
2. Description of the Prior Art
As one method for reading out signals from a solid state image sensor, there has been proposed a method such as that shown in FIG. 1, at respective horizontal intervals, or Nth, (N+1)th, (N+2)th, . . . horizontal intervals of a frame, signals of two adjacent rows of sensing elements are simultaneously read out in mixed condition, while at respective horizontal intervals of even-numbered fields, or (N+263)th, (N+264)th, (N+265)th, . . . horizontal intervals of a frame, signals of two adjacent rows, which are shifted by one row relative to the former, are simultaneously read out. In this case, an alignment of unit sensing elements in a direction corresponding to the horizontal direction of the picture screen is taken as a row.
Though having an advantage such as less visual persistence, this method has not been used in a color pickup system by reason of difficult color separation.
In this method, a pair of unit sensing elements read out simultaneously are alternated at every field. Now, let it be arranged to use such a color filter that, for example, as shown in FIG. 2, a color element of the filter corresponding to one unit sensing element for penetrating therethrough a red color light and a color element thereof corresponding to one unit sensing element for penetrating therethrough a blue color light are sequentially alternated in a direction corresponding to the vertical direction of the picture screen. In this case, at odd-numbered field and also at even-numbered field a red and blue mixed color, namely, a magenta color signal, will be picked up at respective horizontal intervals so that a red color signal and a blue color signal can not be separated from each other.
It is also arranged to use such a color filter that, as shown in FIG. 3, color elements of the filter corresponding to two unit sensing elements for penetrating therethrough a red color light and color elements thereof corresponding to two unit sensing elements for penetrating therethrough a blue color light are sequentially alternated in the vertical direction. In this case, at an odd-numbered field the red color signal and the blue color signal are picked up alternately at every horizontal interval, but at an even-numbered field the red and blue mixed color signal will be picked up at each horizontal interval. In this case, if signals at odd-numbered field are stored for one field and these signals are modified with signals read-out at even-numbered field, the red color signal and the blue color signal may be separated from each other even at the even-numbered field. However, it is complicated and not practical.